Bipolar membrane electrodialysis device for preparing perfluorinated sulfonic acid resin solution and preparation method

Abstract

The invention belongs to the technical field of preparation of perfluorinated sulfonic acid resin, and particularly relates to a bipolar membrane electrodialysis device for preparing a perfluorinated sulfonic acid resin solution and a preparation method. The device comprises an electrolytic bath, an anode plate arranged at one end of the electrolytic bath, a cathode plate arranged at the other end of the electrolytic bath, and an anode chamber, a bipolar membrane assembly and a cathode chamber which are arranged between the anode plate and the cathode plate, wherein the anode chamber and the cathode chamber are connected in series; the bipolar membrane assembly comprises a bipolar membrane, an acid chamber, a cation exchange membrane and an alkali chamber. According to the preparation method of the perfluorosulfonic acid resin solution, the bipolar membrane electrodialysis device is used for transformation preparation of the perfluorosulfonic acid resin solution for the first time, a bipolar membrane is used for directly dissociating water to generate H < + > and OH, the perfluorosulfonic acid resin solution is transformed into the perfluorosulfonic acid resin solution through a one-step method, and compared with a traditional method, the preparation method has the advantages that the cost is low, and the efficiency is high. According to the method disclosed by the invention, the transformation rate and the yield are greatly improved, the time cost and the labor cost are greatly saved, and pollutant-free emission can be realized.

Description

Technical Field

[0001] This application belongs to the field of preparation technology of perfluorosulfonic acid resins, specifically relating to a bipolar membrane electrodialysis device and preparation method for preparing perfluorosulfonic acid resin solutions. Background Technology

[0002] Perfluorosulfonic acid proton exchange membranes (PTMs) are solid polymer electrolytes with advantages such as high conductivity, high mechanical strength, good chemical stability, and good thermal stability. They are widely used in fuel cells, water electrolysis for hydrogen production, chlor-alkali industries, energy storage batteries, and gas sensors. Perfluorosulfonic acid resin solution is a key material in the production of PTMs, and its preparation process not only affects the performance of the PTM but also directly impacts its production efficiency and cost.

[0003] The traditional process for preparing perfluorosulfonic acid resin solution is as follows: perfluorosulfonate resin powder is repeatedly impregnated and acidified with a high-concentration acid solution to transform it into perfluorosulfonic acid resin. Then, it is repeatedly washed with deionized water to remove residual acid and salt-type byproducts before drying. The washed and dried perfluorosulfonic acid resin is then dissolved and dispersed in a low-boiling-point aqueous alcohol solvent to obtain the perfluorosulfonic acid resin solution.

[0004] Traditional methods for preparing perfluorosulfonic acid resin solutions have the following problems: the acidification and transformation of perfluorosulfonate resin in powder form is inefficient; the transformation requires multiple immersions in high-concentration acid solutions for acidification, followed by multiple washes with deionized water to remove residual acid and byproducts, generating a large amount of waste acid and wastewater, and the process is cumbersome, time-consuming, and labor-intensive; perfluorosulfonic acid resin is only slightly soluble in deionized water, and resin loss occurs during the washing process, resulting in low yields in the transformation and washing processes, which increases the cost of resin preparation. Summary of the Invention

[0005] This application provides a bipolar membrane electrodialysis device and preparation method for preparing perfluorosulfonic acid resin solution, aiming to solve the problems of cumbersome preparation process, large amount of waste acid and wastewater generation, low yield and high cost of existing perfluorosulfonic acid resin solution preparation.

[0006] The first aspect of this application provides a bipolar membrane electrodialysis device for preparing perfluorosulfonic acid resin solution, including an electrolytic cell, an anode plate disposed at one end of the electrolytic cell, a cathode plate disposed at the other end of the electrolytic cell, and an anode chamber, a bipolar membrane assembly, and a cathode chamber disposed between the anode plate and the cathode plate, wherein the anode chamber and the cathode chamber are connected in series.

[0007] The bipolar membrane assembly includes a bipolar membrane, an acid chamber, a cation exchange membrane, and an alkaline chamber.

[0008] According to some embodiments of the bipolar membrane electrodialysis apparatus for preparing perfluorosulfonic acid resin solution described in this application, both the anode plate and the cathode plate are coated titanium electrodes; preferably, the coated titanium electrode includes a titanium plate and a titanium plate coated with a noble metal oxide coating; more preferably, the noble metal in the noble metal oxide includes one or more of ruthenium (Ru), iridium (Ir) and platinum (Pt).

[0009] According to some embodiments of the bipolar membrane electrodialysis apparatus for preparing perfluorosulfonic acid resin solutions described in this application, the bipolar membrane includes a cation exchange layer, an anion exchange layer, and an intermediate catalyst layer located between the cation exchange layer and the anion exchange layer. The cation exchange layer faces the cathode, the anion exchange layer faces the anode, and the intermediate catalyst layer is tightly sandwiched between the cation exchange layer and the anion exchange layer.

[0010] The cation exchange layer comprises a polymer material containing functional groups with fixed negative charges; preferably, the functional groups with fixed negative charges comprise one or more of sulfonic acid groups, phosphate groups, and carboxylic acid groups; preferably, the polymer in the polymer material containing the functional groups with fixed negative charges comprises one or more of polystyrene, polyphenylene ether, sodium alginate, modified chitosan, polyvinyl chloride, and polyetheretherketone. The anion exchange layer comprises a polymer material containing functional groups with fixed positive charges; preferably, the functional groups with fixed positive charges comprise one or more of quaternary ammonium groups, tertiary ammonium groups, and secondary ammonium groups; preferably, the polymer in the polymer material containing the functional groups with fixed positive charges comprises one or more of polystyrene, polysulfone, and polyvinylidene fluoride. The intermediate catalyst layer comprises a polymer matrix network and a catalytically active component; the polymer matrix network comprises one or more of polyvinyl alcohol, polyacrylonitrile, and polysulfone; the catalytically active component comprises one or more of iron hydroxide (Fe(OH)3), chromium hydroxide (Cr(OH)3), aluminum hydroxide (Al(OH)3), silicon dioxide (SiO2), titanium dioxide (TiO2), and zirconium dioxide (ZrO2); the catalytically active component is uniformly dispersed in the polymer matrix network.

[0011] According to some embodiments of the bipolar membrane electrodialysis device for preparing perfluorosulfonic acid resin solutions described in this application, the cation exchange membrane comprises a polymer material containing functional groups with fixed negative charges; preferably, the functional groups with fixed negative charges comprise one or more of sulfonic acid groups, phosphate groups, and carboxylic acid groups; preferably, the polymer in the polymer material containing the functional groups with fixed negative charges comprises one or more of tetrafluoroethylene-perfluorovinyl ether copolymer, polystyrene, polyphenylene ether, sodium alginate, modified chitosan, polyvinyl chloride, and polyetheretherketone.

[0012] According to some embodiments of the bipolar membrane electrodialysis apparatus for preparing perfluorosulfonic acid resin solution described in this application, the number of membrane modules is greater than or equal to 1, and several membrane modules are connected in series.

[0013] A second aspect of this application provides a method for preparing a perfluorosulfonic acid resin solution using the bipolar membrane electrodialysis apparatus described in the first aspect of this application, comprising the following steps: A salt solution is added to the anode and cathode chambers of the bipolar membrane electrodialysis device, a perfluorosulfonate resin solution is added to the acid chamber, and water is added to the alkali chamber; a direct current is passed through to cause a water dissociation reaction in the electrolytic cell to obtain a perfluorosulfonate resin solution.

[0014] According to some embodiments of the method for preparing perfluorosulfonic acid resin solution described in this application, the mass concentration of the salt solution is 2%-8%.

[0015] According to some embodiments of the method for preparing perfluorosulfonic acid resin solution described in this application, the salt solution includes a sodium sulfate solution.

[0016] According to some embodiments of the method for preparing perfluorosulfonic acid resin solution described in this application, the mass concentration of the perfluorosulfonate type resin solution is 1%-30%.

[0017] According to some embodiments of the method for preparing perfluorosulfonic acid resin solution described in this application, the viscosity of the perfluorosulfonate type resin solution is 2.0-100.0 mPa•s.

[0018] According to some embodiments of the method for preparing perfluorosulfonic acid resin solution described in this application, the particle size of the perfluorosulfonate resin in the perfluorosulfonate resin solution is 50-500 nm.

[0019] According to some embodiments of the method for preparing perfluorosulfonic acid resin solution described in this application, the solvent used in the perfluorosulfonate type resin solution includes one or more of water, methanol, ethanol, isopropanol, n-propanol and n-butanol.

[0020] According to some embodiments of the method for preparing perfluorosulfonic acid resin solution described in this application, the current density of the water dissociation reaction is 10-100 mA / cm². 2 The temperature is 10-60℃.

[0021] According to some embodiments of the method for preparing perfluorosulfonic acid resin solution described in this application, the linear flow velocity of the solution in the anode chamber, cathode chamber, acid chamber, and alkali chamber is independently 0.1-10 cm / s.

[0022] According to some embodiments of the method for preparing perfluorosulfonic acid resin solution described in this application, during the water dissociation reaction, when the concentration of the solution in the alkali chamber remains constant, the energizing is stopped, and the perfluorosulfonic acid resin solution flows out from the acid chamber.

[0023] The beneficial effects of this application include: the method for preparing perfluorosulfonic acid resin solution described in this application is the first to utilize a bipolar membrane electrodialysis device to prepare perfluorosulfonic acid resin solution, and utilizes the bipolar membrane to directly dissociate water to generate H+. + and OH The method described in this application converts perfluorosulfonate resin solution into perfluorosulfonic acid resin solution in a one-step process. Compared with traditional preparation methods, the conversion rate and yield of the method described in this application are greatly improved, and time and labor costs are significantly saved.

[0024] The method for preparing perfluorosulfonic acid resin solution described in this application uses bipolar membrane electrodialysis to transform perfluorosulfonic acid resin solution. During this process, only acid solution (perfluorosulfonic acid resin solution) and a fixed volume of alkali solution (potassium hydroxide / sodium solution) are generated. Moreover, the alkali solution has a high recovery value. Compared with the traditional preparation process that generates a large amount of wastewater and waste acid, it can achieve zero pollutant discharge. Attached Figure Description

[0025] Figure 1 This is a schematic diagram illustrating the principle of preparing perfluorosulfonic acid resin solution using the bipolar membrane electrodialysis device described in Embodiment 2 of this application; Wherein: BP is a bipolar membrane, layer A is an anion exchange layer, layer C is a cation exchange layer, and C is a cation exchange membrane. Detailed Implementation

[0026] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0028] This application provides a bipolar membrane electrodialysis device for preparing perfluorosulfonic acid resin solution, including an electrolytic cell, an anode plate disposed at one end of the electrolytic cell, a cathode plate disposed at the other end of the electrolytic cell, and an anode chamber, a bipolar membrane assembly, and a cathode chamber disposed between the anode plate and the cathode plate, wherein the anode chamber and the cathode chamber are connected in series. The bipolar membrane assembly includes a bipolar membrane, an acid chamber, a cation exchange membrane, and an alkaline chamber.

[0029] The bipolar membrane electrodialysis apparatus for preparing perfluorosulfonic acid resin solution described in this application can efficiently prepare perfluorosulfonic acid resin solution in one step using perfluorosulfonate type resin solution as raw material. The anode chamber and cathode chamber are connected in series, allowing the solution in the two chambers to be pooled and recycled.

[0030] In some embodiments of this application, both the anode plate and the cathode plate are coated titanium electrodes.

[0031] In some embodiments of this application, the coated titanium electrode includes a titanium plate and a titanium plate coated with a noble metal oxide coating.

[0032] In some embodiments of this application, the noble metal in the noble metal oxide includes one or more of ruthenium (Ru), iridium (Ir), and platinum (Pt).

[0033] In some embodiments of this application, the bipolar membrane includes a cation exchange layer, an anion exchange layer, and an intermediate catalyst layer located between the cation exchange layer and the anion exchange layer; The cation exchange layer comprises a polymer material containing functional groups with fixed negative charges; preferably, the functional groups with fixed negative charges comprise one or more of sulfonic acid groups, phosphate groups, and carboxylic acid groups; preferably, the polymer in the polymer material containing the functional groups with fixed negative charges comprises one or more of polystyrene, polyphenylene ether, sodium alginate, modified chitosan, polyvinyl chloride, and polyetheretherketone. The anion exchange layer comprises a polymer material containing functional groups with fixed positive charges; preferably, the functional groups with fixed positive charges comprise one or more of quaternary ammonium groups, tertiary ammonium groups, and secondary ammonium groups; preferably, the polymer in the polymer material containing the functional groups with fixed positive charges comprises one or more of polystyrene, polysulfone, and polyvinylidene fluoride. The intermediate catalyst layer comprises a polymer matrix network and a catalytically active component; the polymer matrix network comprises one or more of polyvinyl alcohol, polyacrylonitrile, and polysulfone, and the catalytically active component comprises one or more of iron hydroxide (Fe(OH)3), chromium hydroxide (Cr(OH)3), aluminum hydroxide (Al(OH)3), silicon dioxide (SiO2), titanium dioxide (TiO2), and zirconium dioxide (ZrO2).

[0034] In some embodiments of this application, the cation exchange membrane comprises a polymer material containing functional groups for fixing negative charges; preferably, the functional groups for fixing negative charges comprise one or more of sulfonic acid groups, phosphate groups, and carboxylic acid groups; preferably, the polymer in the polymer material containing the functional groups for fixing negative charges comprises one or more of tetrafluoroethylene-perfluorovinyl ether copolymer, polystyrene, polyphenylene ether, sodium alginate, modified chitosan, polyvinyl chloride, and polyetheretherketone.

[0035] In a preferred embodiment, the cation exchange layer of the bipolar membrane is sulfonated polystyrene, the anion exchange layer is quaternized polysulfone, the catalyst layer matrix is ​​polyvinyl alcohol, and the catalytic active component is iron hydroxide (Fe(OH)3).

[0036] As a preferred embodiment, the cation exchange membrane is a perfluorosulfonic acid proton exchange membrane.

[0037] In some embodiments of this application, the number of membrane modules is greater than or equal to 1, and several membrane modules are connected in series.

[0038] This application also provides a method for preparing a perfluorosulfonic acid resin solution using the bipolar membrane electrodialysis device described in the first aspect of this application, comprising the following steps: Salt solution is added to the anode and cathode chambers of the bipolar membrane electrodialysis device, perfluorosulfonate resin solution (PFSA-SO3Na / K) is added to the acid chamber, and water is added to the alkali chamber; direct current is passed through to cause a water dissociation reaction in the electrolytic cell to obtain perfluorosulfonate resin solution.

[0039] The hydrogen ions (H+) dissociated from the bipolar membrane electrodialysis device + ) enters the acid chamber and reacts with perfluorosulfonic acid anions (PFSA-SO3). ) combine to form perfluorosulfonic acid (PFSA-SO3H); hydroxide ions (OH-) are released from hydrolysis within the bipolar membrane. ) enter the alkali chamber, and sodium / potassium ions (Na+) enter the alkali chamber through the cation exchange membrane from the acid chamber. + / K + They combine to form sodium hydroxide or potassium hydroxide (NaOH / KOH).

[0040] The preparation method described in this application has the advantages of simple process, high efficiency and yield, low cost, and environmental and personnel-friendly characteristics, and is suitable for the batch continuous production of perfluorosulfonic acid resin solutions.

[0041] In some embodiments of this application, the mass concentration of the salt solution is 2%-8%; for example, 2%, 3%, 5%, 6%, 8%, etc.

[0042] In some embodiments of this application, the salt solution includes a sodium sulfate solution.

[0043] In some embodiments of this application, the mass concentration of the perfluorosulfonate type resin solution is 1%-30%, such as 1%, 5%, 8%, 12%, 15%, 20%, 23%, 28%, 30%, etc.

[0044] In some embodiments of this application, the viscosity of the perfluorosulfonate resin solution is 2.0-100.0 mPa•s, such as 2 mPa•s, 5 mPa•s, 10 mPa•s, 18 mPa•s, 23 mPa•s, 37 mPa•s, 45 mPa•s, 53 mPa•s, 70 mPa•s, 80 mPa•s, 90 mPa•s, 100 mPa•s, etc.

[0045] In some embodiments of this application, the theoretical EW value of the perfluorosulfonate resin solution is 600-1500 g / mol; the theoretical EW value of the perfluorosulfonate resin solution is the EW value after the perfluorosulfonate resin is acidified into perfluorosulfonic acid resin.

[0046] In some embodiments of this application, the particle size of the perfluorosulfonate resin in the perfluorosulfonate resin solution is 50-500 nm; for example, 50 nm, 100 nm, 200 nm, 260 nm, 300 nm, 400 nm, 500 nm, etc.

[0047] In some embodiments of this application, the solvent used in the perfluorosulfonate type resin solution includes one or more of water, methanol, ethanol, isopropanol, n-propanol, and n-butanol.

[0048] In some embodiments of this application, the current density of the water dissociation reaction is 10-100 mA / cm². 2 For example, 10mA / cm2 20mA / cm 2 50mA / cm 2 80mA / cm 2 100mA / cm 2 Temperatures range from 10 to 60°C, such as 10°C, 20°C, 30°C, 50°C, 60°C, etc.

[0049] In some embodiments of this application, the linear flow velocity of the solution in the anode chamber, cathode chamber, acid chamber, and alkali chamber is independently 0.1-10 cm / s, for example 0.1 cm / s, 0.5 cm / s, 1.3 cm / s, 2.6 cm / s, 3.7 cm / s, 5 cm / s, 8 cm / s, 10 cm / s, etc.

[0050] In some embodiments of this application, during the water dissociation reaction, when the concentration of the solution in the alkali chamber remains constant, the power is stopped and the perfluorosulfonic acid resin solution flows out from the acid chamber.

[0051] The technical solution of this application will be further described below with reference to specific embodiments.

[0052] Example 1 A bipolar membrane electrodialysis apparatus for preparing perfluorosulfonic acid resin solution includes an electrolytic cell, a titanium-coated ruthenium dioxide anode plate disposed at one end of the electrolytic cell, a titanium-coated ruthenium dioxide cathode plate disposed at the other end of the electrolytic cell, and an anode chamber, a bipolar membrane assembly, and a cathode chamber disposed between the anode plate and the cathode plate, wherein the anode chamber and the cathode chamber are connected in series. The bipolar membrane assembly includes a bipolar membrane, an acid chamber, a cation exchange membrane, and an alkali chamber. In this embodiment, there are two bipolar membrane assemblies connected in series. The cation exchange layer of the bipolar membrane used in this embodiment is sulfonated polystyrene, the anion exchange layer is quaternized polysulfone, the catalyst layer matrix is ​​polyvinyl alcohol, the catalytic active component is iron hydroxide (Fe(OH)3), and the area of ​​the bipolar membrane is 75×195mm. The cation exchange membrane is a perfluorosulfonic acid proton exchange membrane with an area of ​​75×195mm.

[0053] Example 2 A method for preparing a perfluorosulfonic acid resin solution using the bipolar membrane electrodialysis apparatus described in Example 1 includes the following steps: 38.94 g of sodium perfluorosulfonate resin with a theoretical EW value of 1000 g / mol is taken, and a sodium perfluorosulfonate resin solution with a solid content of 4.88 wt%, a viscosity of 8 mPa•s, and a particle size of 100-200 nm is prepared using water and ethanol in a 1:1 mass ratio as solvents. 797.92 g of the prepared sodium perfluorosulfonate resin solution is added to the acid chamber of the bipolar membrane electrodialysis apparatus described in Example 1. 400 mL of pure water is added to the alkali chamber. 1000 mL of a 5.0% sodium sulfate aqueous solution is added to both the anode and cathode chambers. A direct current is applied for voltage stabilization, with an output voltage of 25 V. The upper limit of the current density is set to 30 mA / cm². 2 The operating temperature is 30℃, and the linear flow velocity of the solutions in the anode, cathode, acid, and alkali chambers is 3 cm / s. During the operation of the bipolar membrane electrodialysis device, the solution in the alkali chamber is sampled and analyzed every 10 minutes. The power is stopped after the conductivity of the solution in the alkali chamber remains constant. 797.33 g of perfluorosulfonic acid resin solution with a solid content of 4.78 wt% and an EW value of 1009 g / mol is obtained from the acid chamber.

[0054] Example 3 A method for preparing perfluorosulfonic acid resin solution using the bipolar membrane electrodialysis apparatus described in Example 1 includes the following steps: Take 26.98g of sodium perfluorosulfonate resin with a theoretical EW value of 850g / mol, and prepare a sodium perfluorosulfonate resin solution with a solid content of 3.37wt%, a viscosity of 8mPa•s, and a particle size of 100-200nm using water and ethanol in a 1:1 mass ratio as solvents. Add 800.59g of the prepared sodium perfluorosulfonate resin solution to the acid chamber of the bipolar membrane electrodialysis device described in Example 1, add 400mL of pure water to the alkali chamber, and add 1000mL of 5.0% sodium sulfate aqueous solution to the anode and cathode chambers respectively. Apply direct current for voltage stabilization, with an output voltage of 25V. Set the upper limit of the current density to 30mA / cm. 2 The operating temperature is 30℃, and the linear flow velocity of the solutions in the anode, cathode, acid, and alkali chambers is 3 cm / s. During the operation of the bipolar membrane electrodialysis device, the solution in the alkali chamber is sampled and analyzed every 10 minutes. The power is stopped after the conductivity of the solution in the alkali chamber remains constant. 794.22 g of perfluorosulfonic acid resin solution with a solid content of 3.25 wt% and an EW value of 868 g / mol is obtained from the acid chamber.

[0055] Example 4 A method for preparing perfluorosulfonic acid resin solution using the bipolar membrane electrodialysis apparatus described in Example 1 includes the following steps: Take 31.24 g of potassium perfluorosulfonate resin with a theoretical EW value of 850 g / mol, and prepare a potassium perfluorosulfonate resin solution with a solid content of 6.24 wt%, a viscosity of 8.9 mPa•s, and a particle size of 100-200 nm using water and ethanol in a 1:1 mass ratio as solvents. Add 500.64 g of the prepared potassium perfluorosulfonate resin solution to the acid chamber of the bipolar membrane electrodialysis device described in Example 1, add 400 mL of pure water to the alkali chamber, and add 1000 mL of 5.0% sodium sulfate aqueous solution to the anode and cathode chambers respectively. Apply direct current for voltage stabilization, with an output voltage of 25 V. Set the upper limit of the current density to 30 mA / cm². 2 The operating temperature is 30℃, and the linear flow velocity of the solutions in the anode, cathode, acid, and alkali chambers is 3 cm / s. During the operation of the bipolar membrane electrodialysis device, the solution in the alkali chamber is sampled and analyzed every 10 minutes. The power is stopped after the conductivity of the solution in the alkali chamber remains constant. 499.75 g of perfluorosulfonic acid resin solution with a solid content of 6.13 wt% and an EW value of 872 g / mol is obtained from the acid chamber.

[0056] Example 5 A method for preparing perfluorosulfonic acid resin solution using the bipolar membrane electrodialysis apparatus described in Example 1 includes the following steps: Take 46.84g of potassium perfluorosulfonate resin with a theoretical EW value of 850g / mol, and prepare a potassium perfluorosulfonate resin solution with a solid content of 9.86wt%, a viscosity of 18.5mPa•s, and a particle size of 100-200nm using water and ethanol in a 1:1 mass ratio as solvents. Add 475.00g of the prepared potassium perfluorosulfonate resin solution to the acid chamber of the bipolar membrane electrodialysis device described in Example 1. Add 300mL of pure water to the alkali chamber, and add 1000mL of 5.0% sodium sulfate aqueous solution to the anode and cathode chambers respectively. Apply direct current for voltage stabilization, with an output voltage of 25V. Set the upper limit of the current density to 30mA / cm. 2 The operating temperature is 30℃, and the linear flow velocity of the solutions in the anode chamber, cathode chamber, acid chamber, and alkali chamber is 5 cm / s. During the operation of the bipolar membrane electrodialysis device, the solution in the alkali chamber is sampled and analyzed every 10 minutes. The power is stopped after the conductivity of the solution in the alkali chamber remains constant. 488.73 g of perfluorosulfonic acid resin solution with a solid content of 9.20 wt% and an EW value of 866 g / mol is obtained from the acid chamber.

[0057] Example 6 The difference between the preparation method of the perfluorosulfonic acid resin solution in Example 6 and that in Example 2 is that, in the preparation process of the perfluorosulfonic acid resin solution in Example 6, water and isopropanol in a mass ratio of 1:1 are used as solvents to prepare a sodium perfluorosulfonate type resin solution with a solid content of 4.88 wt%, a viscosity of 46.2 mPa•s, and a particle size of 100-200 nm. Finally, 788.13 g of a perfluorosulfonic acid resin solution with a solid content of 4.87 wt% and an EW value of 1048 g / mol is obtained from the acid chamber.

[0058] Example 7 The difference between the preparation method of the perfluorosulfonic acid resin solution in Example 7 and that in Example 5 is that, in the preparation process of the perfluorosulfonic acid resin solution in Example 7, water and ethanol in a mass ratio of 2:1 are used as solvents to prepare a potassium perfluorosulfonate type resin solution with a solid content of 15.35 wt%, a viscosity of 18.9 mPa•s, and a particle size of 100-200 nm. Finally, 477.32 g of a perfluorosulfonic acid resin solution with a solid content of 15.38 wt% and an EW value of 854 g / mol is obtained from the acid chamber.

[0059] Example 8 The difference between the preparation method of the perfluorosulfonic acid resin solution in Example 8 and that in Example 5 is that, in the preparation process of the perfluorosulfonic acid resin solution in Example 8, water and ethanol in a mass ratio of 2:1 are used as solvents to prepare a potassium perfluorosulfonate type resin solution with a solid content of 25.53 wt%, a viscosity of 66.8 mPa•s, and a particle size of 100-200 nm. Finally, 485.08 g of a perfluorosulfonic acid resin solution with a solid content of 25.47 wt% and an EW value of 883 g / mol is obtained from the acid chamber.

[0060] Comparative Example 1 The difference between the preparation method of the perfluorosulfonic acid resin solution in Comparative Example 1 and Example 5 is that, in the preparation process of the perfluorosulfonic acid resin solution in Comparative Example 1, water and ethanol in a mass ratio of 2:1 are used as solvents to prepare a potassium perfluorosulfonate type resin solution with a solid content of 1.03%, a viscosity of 5.6 mPa•s, and a particle size of 100-200 nm. Finally, 450.27 g of a perfluorosulfonic acid resin solution with a solid content of 1.05 wt% and an EW value of 952 g / mol was obtained from the acid chamber. Comparative Example 2 The difference between the preparation method of the perfluorosulfonic acid resin solution in Comparative Example 2 and Example 5 is that, in the preparation process of the perfluorosulfonic acid resin solution in Comparative Example 2, water and ethanol in a mass ratio of 2:1 are used as solvents to prepare a potassium perfluorosulfonate type resin solution with a solid content of 0.50%, a viscosity of 2.3 mPa•s, and a particle size of 100-200 nm. Finally, 471.33 g of a perfluorosulfonic acid resin solution with a solid content of 0.49 wt% and an EW value of 988 g / mol was obtained from the acid chamber. Comparative Example 3 The difference between the preparation method of the perfluorosulfonic acid resin solution in Comparative Example 3 and that in Example 2 is that, in the preparation process of the perfluorosulfonic acid resin solution in Comparative Example 3, water and isopropanol in a mass ratio of 1:2 were used as solvents to prepare a sodium perfluorosulfonate type resin solution with a solid content of 4.88 wt%, a viscosity of 84.5 mPa•s, and a particle size of 100-200 nm. Finally, 791.66 g of a perfluorosulfonic acid resin solution with a solid content of 4.85 wt% and an EW value of 1123 g / mol was obtained from the acid chamber.

[0061] Comparative Example 4 The difference between the preparation method of the perfluorosulfonic acid resin solution in Comparative Example 4 and that in Example 2 is that, in the preparation process of the perfluorosulfonic acid resin solution in Comparative Example 4, water and isopropanol in a mass ratio of 1:3 were used as solvents to prepare a sodium perfluorosulfonate type resin solution with a solid content of 4.88 wt%, a viscosity of 158.8 mPa•s, and a particle size of 100-200 nm. Finally, 783.34 g of a perfluorosulfonic acid resin solution with a solid content of 4.75 wt% and an EW value of 1205 g / mol was obtained from the acid chamber.

[0062] Effect Study on the Preparation Methods of Perfluorosulfonic Acid Resin Solutions in Examples 2-8 and Comparative Examples 1-4 of this Application Conversion rate: The conversion rate is calculated based on the theoretical EW value (EW1) of the resin and the actual measured EW value (EW2) after conversion.

[0063] Transformation rate η = (1 ÷ EW2) / (1 ÷ EW1) Yield: The yield is calculated based on the resin mass in the solution before and after the conversion.

[0064] Yield γ=m2 s2 / m1 s1 Where: m1 is the mass of the perfluorosulfonate resin solution added to the acid chamber of the bipolar membrane electrodialysis device; m2 is the mass of the perfluorosulfonic acid resin solution obtained in the acid chamber; s1 is the solid content of the perfluorosulfonate resin solution added to the acid chamber; s2 is the solid content of the perfluorosulfonic acid resin solution obtained in the acid chamber; The results are shown in Table 1.

[0065] Table 1

[0066] As shown in Table 1, the bipolar membrane electrodialysis method described in this application for preparing perfluorosulfonic acid resin solution has a high yield, exceeding 95%. Compared to traditional acidification conversion methods, the method for preparing perfluorosulfonic acid resin solution described in this application eliminates repeated acidification and washing steps, thus avoiding significant resin loss.

[0067] As can be seen from Examples 2-5, within a suitable viscosity range, the perfluorosulfonic acid resin solution prepared by bipolar membrane electrodialysis exhibits a high conversion rate (>97%).

[0068] Comparing Examples 2, 6, 3, and 4, it can be seen that increasing the viscosity of the perfluorosulfonate resin solution significantly reduces the resin conversion rate. When the viscosity exceeds 80 mPa•s, the conversion rate is below 90%, and it no longer offers a significant advantage over traditional preparation methods. The decrease in resin conversion rate is attributed to the fact that the high viscosity of the resin solution reduces the ion movement and exchange rates, thereby decreasing the conversion efficiency.

[0069] Comparing Examples 5 and 7, it can be seen that when the viscosity of the perfluorosulfonate resin solution is similar, increasing the solid content of the solution improves the conversion rate of the resin to a certain extent. This is because the increase in solid content increases the initial charge concentration of the solution, promotes ion exchange in the positive reaction direction, and thus further improves the resin conversion rate.

[0070] Comparing Examples 5 and 7-8, it can be seen that while the solid content of the perfluorosulfonate resin solution increases significantly, the solution viscosity also increases, which in turn reduces the resin conversion rate.

[0071] Comparing Examples 3-5, Comparative Example 1, and Comparative Example 2, it can be seen that when the solid content of the perfluorosulfonate resin solution is less than 1 wt%, the conversion rate of the resin is less than 90%, which no longer has a significant advantage compared to the traditional preparation method. When the solid content of the resin solution is too low, the initial charge concentration of the solution is very low, which cannot effectively promote the ion exchange reaction, reduces the rate of the ion exchange reaction, and thus reduces the conversion efficiency.

[0072] Based on the above analysis, and considering the influence of solution viscosity and solid content on resin conversion rate, the preferred solid content range for perfluorosulfonate resin solutions is 1-30 wt%, and the viscosity should not exceed 80 mPa•s.

[0073] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A bipolar membrane electrodialysis apparatus for preparing perfluorosulfonic acid resin solution, characterized in that, It includes an electrolytic cell, an anode plate disposed at one end of the electrolytic cell, a cathode plate disposed at the other end of the electrolytic cell, and an anode chamber, a bipolar film assembly, and a cathode chamber disposed between the anode plate and the cathode plate, wherein the anode chamber and the cathode chamber are connected in series; The bipolar membrane assembly includes a bipolar membrane, an acid chamber, a cation exchange membrane, and an alkaline chamber.

2. The bipolar membrane electrodialysis apparatus for preparing perfluorosulfonic acid resin solution according to claim 1, characterized in that, Both the anode plate and the cathode plate are coated titanium electrodes; preferably, the coated titanium electrode comprises a titanium plate and a titanium plate coated with a noble metal oxide coating; more preferably, the noble metal in the noble metal oxide comprises one or more of ruthenium (Ru), iridium (Ir) and platinum (Pt); And / or, the bipolar membrane includes a cation exchange layer, an anion exchange layer, and an intermediate catalyst layer located between the cation exchange layer and the anion exchange layer; The cation exchange layer comprises a polymer material containing functional groups with fixed negative charges; preferably, the functional groups with fixed negative charges comprise one or more of sulfonic acid groups, phosphate groups, and carboxylic acid groups; preferably, the polymer in the polymer material containing the functional groups with fixed negative charges comprises one or more of polystyrene, polyphenylene ether, sodium alginate, modified chitosan, polyvinyl chloride, and polyetheretherketone. The anion exchange layer comprises a polymer material containing functional groups with fixed positive charges; preferably, the functional groups with fixed positive charges comprise one or more of quaternary ammonium groups, tertiary ammonium groups, and secondary ammonium groups; preferably, the polymer in the polymer material containing the functional groups with fixed positive charges comprises one or more of polystyrene, polysulfone, and polyvinylidene fluoride. The intermediate catalyst layer comprises a polymer matrix network and a catalytically active component; the polymer matrix network comprises one or more of polyvinyl alcohol, polyacrylonitrile, and polysulfone, and the catalytically active component comprises one or more of iron hydroxide (Fe(OH)3), chromium hydroxide (Cr(OH)3), aluminum hydroxide (Al(OH)3), silicon dioxide (SiO2), titanium dioxide (TiO2), and zirconium dioxide (ZrO2); And / or, the cation exchange membrane comprises a polymer material containing functional groups for fixing negative charges; preferably, the functional groups for fixing negative charges comprise one or more of sulfonic acid groups, phosphate groups, and carboxylic acid groups; preferably, the polymer in the polymer material containing the functional groups for fixing negative charges comprises one or more of tetrafluoroethylene-perfluorovinyl ether copolymer, polystyrene, polyphenylene ether, sodium alginate, modified chitosan, polyvinyl chloride, and polyetheretherketone.

3. The bipolar membrane electrodialysis apparatus for preparing perfluorosulfonic acid resin solution according to claim 1, characterized in that, The number of membrane modules is greater than or equal to 1, and several membrane modules are connected in series.

4. A method for preparing a perfluorosulfonic acid resin solution using the bipolar membrane electrodialysis apparatus according to any one of claims 1-3, characterized in that, Includes the following steps: A salt solution is added to the anode and cathode chambers of the bipolar membrane electrodialysis device, a perfluorosulfonate resin solution is added to the acid chamber, and water is added to the alkali chamber; a direct current is passed through to cause a water dissociation reaction in the electrolytic cell to obtain a perfluorosulfonate resin solution.

5. The method for preparing perfluorosulfonic acid resin solution using a bipolar membrane electrodialysis device according to claim 4, characterized in that, The mass concentration of the salt solution is 2%-8%; And / or, the salt solution includes a sodium sulfate solution; And / or, the mass concentration of the perfluorosulfonate resin solution is 1%-30%.

6. The method for preparing perfluorosulfonic acid resin solution using a bipolar membrane electrodialysis device according to claim 4, characterized in that, The viscosity of the perfluorosulfonate resin solution is 2.0-100.0 mPa•s.

7. The method for preparing perfluorosulfonic acid resin solution using a bipolar membrane electrodialysis device according to claim 4, characterized in that, The perfluorosulfonate resin in the solution has a particle size of 50-500 nm. And / or, the solvent used in the perfluorosulfonate type resin solution includes one or more of water, methanol, ethanol, isopropanol, n-propanol and n-butanol.

8. The method for preparing perfluorosulfonic acid resin solution using a bipolar membrane electrodialysis device according to claim 4, characterized in that, The current density of the water dissociation reaction is 10-100 mA / cm². 2 The temperature is 10-60℃.

9. The method for preparing perfluorosulfonic acid resin solution using a bipolar membrane electrodialysis device according to claim 4, characterized in that, The linear flow velocities of the solutions in the anode chamber, cathode chamber, acid chamber, and alkali chamber are each independently 0.1-10 cm / s.

10. The method for preparing perfluorosulfonic acid resin solution using a bipolar membrane electrodialysis device according to claim 4, characterized in that, During the water dissociation reaction, when the concentration of the solution in the alkali chamber remains constant, the current is stopped, and the perfluorosulfonic acid resin solution flows out from the acid chamber.

Images